Every few hours a new community event appears where everybody can participate and top players in leaderboard get a rewards
It would have its own leaderboard and icon
Upon clicking it you would see the time before new event and if event is currently undergoing, you'd see how much time left before it ends.
You'd see all players taking part of the event directly or indirectly
Example of events :
Generate most gold in x hours
Generate most gems in x hours
Spend as much gold as possible
Spend as much gems as possible
Do x amount of quests in x hours
Etc
It would be non stop, day and night, when an event ends, a new one begins after x hours
Small events where top winners earn some gems or gold or shards or whatever
Would make the game even more competitive!